U.S. patent application number 13/741621 was filed with the patent office on 2014-07-17 for extractor for self-loading firearm.
This patent application is currently assigned to Smith & Wesson Corp.. The applicant listed for this patent is Smith & Wesson Corp.. Invention is credited to Seth Joubert, Gary Zukowski.
Application Number | 20140196339 13/741621 |
Document ID | / |
Family ID | 51164054 |
Filed Date | 2014-07-17 |
United States Patent
Application |
20140196339 |
Kind Code |
A1 |
Zukowski; Gary ; et
al. |
July 17, 2014 |
Extractor for Self-Loading Firearm
Abstract
An extractor for a self-loading firearm is mountable on a breech
block and is formed of a body having a hook at one end. The body is
pivotally mounted via a pivot pin. A surface is positioned between
the pivot pin and the hook. The surface is divided into at least
two surface portions offset from one another. One of the surface
portions has a plurality of step surfaces offset from one another.
The step surfaces are used to fix the bar dimension of the hook.
The invention also encompasses a slide on which the extractor is
mounted, as well as a self-loading firearm having the slide. A
method of fitting the extractor to the pistol or slide is also
disclosed.
Inventors: |
Zukowski; Gary; (Ludlow,
MA) ; Joubert; Seth; (Pascoag, RI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Smith & Wesson Corp.; |
|
|
US |
|
|
Assignee: |
Smith & Wesson Corp.
Springfield
MA
|
Family ID: |
51164054 |
Appl. No.: |
13/741621 |
Filed: |
January 15, 2013 |
Current U.S.
Class: |
42/25 |
Current CPC
Class: |
F41A 3/12 20130101; F41A
15/14 20130101; F41A 15/00 20130101 |
Class at
Publication: |
42/25 |
International
Class: |
F41A 15/00 20060101
F41A015/00; F41A 3/12 20060101 F41A003/12 |
Claims
1. An extractor mountable on a breech block of a self-loading
firearm by means of a pivot pin, said extractor comprising: a body
attachable to said breech block and having a hook positioned at one
end thereof; an opening in said body for receiving said pivot pin;
a surface positioned on said body between said opening and said
hook, said surface comprising at least first and second surface
portions, said first surface portion being offset relatively to
said second surface portion, said first surface portion comprising
at least first and second step surfaces, said first step surface
being offset relatively to said second step surface.
2. The extractor according to claim 1, wherein said first surface
portion is positioned proximate to said hook.
3. The extractor according to claim 2, wherein said first step
surface is positioned proximate to said hook.
4. The extractor according to claim 1, wherein said first step
surface is offset from said second step surface from about 0.009
inches to about 0.003 inches.
5. The extractor according to claim 1, wherein said first step
surface is offset from said second step surface about 0.006
inches.
6. An extractor mountable on a breech block of a self-loading
firearm, said extractor comprising: a body attachable to said
breech block and having a hook positioned at one end thereof; a
pivot pin mounted on said body for pivotally attaching said body to
said breech block; a surface positioned on said body between said
pivot pin and said hook, said surface comprising at least first and
second surface portions, said first surface portion being offset
relatively to said second surface portion, said first surface
portion comprising a plurality of step surfaces including at least
a first step surface, a second step surface, and a third step
surface, said first step surface being offset relatively to said
second step surface, said second step surface being offset
relatively to said third step surface.
7. The extractor according to claim 6, wherein said first step
surface is offset from said second step surface by a first
distance, and said second step surface is offset from said third
step surface by a second distance, said first and second distances
being equal to one another.
8. The extractor according to claim 7, wherein said first and
second distances range from about 0.009 inches to about 0.003
inches.
9. The extractor according to claim 7, wherein said first and
second distances are about 0.006 inches.
10. The extractor according to claim 6, wherein said second step
surface is positioned between said first and said third step
surfaces.
11. The extractor according to claim 10, wherein said first surface
portion is positioned proximate to said hook.
12. The extractor according to claim 11, wherein said first step
surface is positioned proximate to said hook.
13. An extractor mountable on a breech block of a self-loading
firearm, said extractor comprising: a body attachable to said
breech block and having a hook positioned at one end thereof; a
pivot pin mounted on said body for pivotally attaching said body to
said breech block; a surface positioned on said body between said
pivot pin and said hook, said surface comprising at least first and
second surface portions, said first surface portion being offset
relatively to said second surface portion, said first surface
portion comprising at least first and second step surfaces, said
first step surface being offset relatively to said second step
surface.
14. The extractor according to claim 13, wherein said first surface
portion is positioned proximate to said hook.
15. The extractor according to claim 14, wherein said first step
surface is positioned proximate to said hook.
16. The extractor according to claim 13, wherein said first step
surface is offset from said second step surface from about 0.009
inches to about 0.003 inches.
17. The extractor according to claim 13, wherein said first step
surface is offset from said second step surface about 0.006
inches.
18. An extractor mountable on a breech block of a self-loading
firearm by means of a pivot pin, said extractor comprising: a body
attachable to said breech block and having a hook positioned at one
end thereof; an opening in said body for receiving said pivot pin;
a surface positioned on said body between said opening and said
hook, said surface comprising at least first and second surface
portions, said first surface portion being offset relatively to
said second surface portion, said first surface portion comprising
a plurality of step surfaces including at least a first step
surface, a second step surface, and a third step surface, said
first step surface being offset relatively to said second step
surface, said second step surface being offset relatively to said
third step surface.
19. The extractor according to claim 18, wherein said first step
surface is offset from said second step surface by a first
distance, and said second step surface is offset from said third
step surface by a second distance, said first and second distances
being equal to one another.
20. The extractor according to claim 19, wherein said first and
second distances range from about 0.009 inches to about 0.003
inches.
21. The extractor according to claim 19, wherein said first and
second distances are about 0.006 inches.
22. The extractor according to claim 18, wherein said second step
surface is positioned between said first and said third step
surfaces.
23. The extractor according to claim 22, wherein said first surface
portion is positioned proximate to said hook.
24. The extractor according to claim 23, wherein said first step
surface is positioned proximate to said hook.
25. A slide for a self-loading pistol, said slide comprising: a
breech block having a breech face; an extractor mounted on said
slide adjacent to said breech face, said extractor comprising a
body having a longitudinal axis oriented transversely to said
breech face, said body comprising a hook projecting beyond said
breech face; a pivot pin mounted on said slide, said pivot pin
being oriented perpendicular to said longitudinal axis of said
body, said body being pivotably mounted on said pivot pin; a
surface positioned on said body between said pivot pin and said
hook, said surface comprising at least first and second surface
portions, said first surface portion being offset toward said
breech block relatively to said second surface portion, said first
surface portion comprising at least first and second step surfaces,
said first step surface being offset toward said breech block
relatively to said second step surface.
26. The slide according to claim 25, wherein said first surface
portion is positioned proximate to said hook.
27. The slide according to claim 25, wherein said first step
surface is positioned proximate to said hook.
28. The slide according to claim 25, wherein said first step
surface is offset from said second step surface from about 0.009
inches to about 0.003 inches.
29. The slide according to claim 25, wherein said first step
surface is offset from said second step surface about 0.006
inches.
30. A slide for a self-loading pistol, said slide comprising: a
breech block having a breech face; an extractor mounted on said
slide adjacent to said breech face, said extractor comprising a
body having a longitudinal axis oriented transversely to said
breech face, said body comprising a hook projecting beyond said
breech face; a pivot pin mounted on said slide, said pivot pin
being oriented perpendicular to said longitudinal axis of said
body, said body being pivotably mounted on said pivot pin; a
surface positioned on said body between said pivot pin and said
hook, said surface comprising at least first and second surface
portions, said first surface portion comprising a plurality of step
surfaces including at least a first step surface, a second step
surface, and a third step surface, said first step surface being
offset toward said breech block relatively to said second step
surface, said second step surface being offset toward said breech
block relatively to said third step surface.
31. The slide according to claim 30, wherein said first step
surface is offset from said second step surface by a first
distance, and said second step surface is offset from said third
step surface by a second distance, said first and second distances
being equal to one another.
32. The slide according to claim 31, wherein said first and second
distances range from about 0.009 inches to about 0.003 inches.
33. The slide according to claim 31, wherein said first and second
distances are about 0.006 inches.
34. The slide according to claim 30, wherein said second step
surface is positioned between said first and said third step
surfaces.
35. The slide according to claim 34, wherein said first surface
portion is positioned proximate to said hook.
36. The slide according to claim 35, wherein said first step
surface is positioned proximate to said hook.
37. A self-loading pistol, comprising: a slide having a breech
block with a breech face; an extractor mounted on said slide
adjacent to said breech face, said extractor comprising a body
having a longitudinal axis oriented transversely to said breech
face, said body comprising a hook projecting beyond said breech
face; a pivot pin mounted on said slide, said pivot pin being
oriented perpendicular to said longitudinal axis of said body, said
body being pivotably mounted on said pivot pin; a surface
positioned on said body between said pivot pin and said hook, said
surface comprising at least first and second surface portions, said
first surface portion being offset toward said breech block
relatively to said second surface portion, said first surface
portion comprising at least first and second step surfaces, said
first step surface being offset toward said breech block relatively
to said second step surface.
38. The pistol according to claim 37, wherein said first surface
portion is positioned proximate to said hook.
39. The pistol according to claim 38, wherein said first step
surface is positioned proximate to said hook.
40. The pistol according to claim 37, wherein said first step
surface is offset from said second step surface from about 0.009
inches to about 0.003 inches.
41. The pistol according to claim 37, wherein said first step
surface is offset from said second step surface about 0.006
inches.
42. A self-loading pistol, comprising: a slide having a breech
block with a breech face; an extractor mounted on said slide
adjacent to said breech face, said extractor comprising a body
having a longitudinal axis oriented transversely to said breech
face, said body comprising a hook projecting beyond said breech
face; a pivot pin mounted on said slide, said pivot pin being
oriented perpendicular to said longitudinal axis of said body, said
body being pivotably mounted on said pivot pin; a surface
positioned on said body between said pivot pin and said hook, said
surface comprising at least first and second surface portions, said
first surface portion being offset toward said breech block
relatively to said second surface portion, said first surface
portion comprising a plurality of step surfaces including at least
a first step surface, a second step surface, and a third step
surface, said first step surface being offset toward said breech
block relatively to said second step surface, said second step
surface being offset toward said breech block relatively to said
third step surface.
43. The pistol according to claim 42, wherein said first step
surface is offset from said second step surface by a first
distance, and said second step surface is offset from said third
step surface by a second distance, said first and second distances
being equal to one another.
44. The pistol according to claim 43, wherein said first and second
distances range from about 0.009 inches to about 0.003 inches.
45. The pistol according to claim 43, wherein said first and second
distances are about 0.006 inches.
46. The pistol according to claim 42, wherein said second step
surface is positioned between said first and said third step
surfaces.
47. The pistol according to claim 46, wherein said first surface
portion is positioned proximate to said hook.
48. The pistol according to claim 47, wherein said first step
surface is positioned proximate to said hook.
49-60. (canceled)
Description
FIELD OF THE INVENTION
[0001] The invention concerns an extractor for a self-loading
firearm, a firearm and its components having such an extractor, and
a method of fitting the extractor to the firearm.
BACKGROUND
[0002] Self-loading or "automatic" pistols use an extractor to
remove a spent casing (during operation) or live round from the
chamber of the pistol. The extractor is mounted on the breech
block, which may be part of the slide for pistols such as the Model
1911 which have a slide. The extractor has a hook that engages a
groove in the base of the cartridge. Engagement between the hook
and cartridge extracts the cartridge (or spent casing) when the
breech block separates from the breech, either during operation or
when the slide is "racked", or moved from battery to open
position.
[0003] The "bar" dimension, the distance between the extractor hook
and an opposite wall of the breech block, is important to ensure
reliable operation of a self-loading pistol. If the bar dimension
is too small, then stripping and chambering of a round during
operation is inhibited. If the bar dimension is too large, then
extraction of the spent casing is erratic. As is typical of
machined parts comprising a mechanism, the dimensions of the parts
will vary within an acceptable tolerance band. Dimensional
tolerances on the extractor and the slide/breech block will combine
(add or subtract) and affect the bar dimension. For some pistols,
such as the Model 1911, the tolerance on the bar dimension is
relatively small. To meet this tolerance, it is found advantageous
to fit the extractor to the slide/breech block.
[0004] Fitting the extractor is a time consuming process whereby
the armorer must assemble the extractor onto the slide/breech
block, measure the bar dimension, and then adjust the size of the
extractor by removing material from the extractor if the bar
dimension is too large. This is done by a "cut and try" method, and
requires considerable skill to effect efficiently, as several
attempts may be required. Removal of material must be done with
care, lest the extractor dimension become too small, thereby
rendering it useless. There is clearly a need for an extractor, and
a method of fitting an extractor to a slide/breech block, which
improves the efficiency of the process.
SUMMARY
[0005] In one example embodiment, the invention comprises an
extractor mountable on a breech block of a self-loading firearm by
means of a pivot pin. In this example the extractor comprises a
body attachable to the breech block. The body has a hook positioned
at one end thereof. An opening in the body is for receiving the
pivot pin. A surface is positioned on the body between the opening
and the hook. The surface comprises at least first and second
surface portions. The first surface portion is offset relatively to
the second surface portion. The first surface portion comprises at
least first and second step surfaces. The first step surface is
offset relatively to the second step surface. In one example
embodiment, the first surface portion is positioned proximate to
the hook. By way of example, the first step surface may also be
positioned proximate to the hook.
[0006] In an example, the first step surface is offset from the
second step surface from about 0.009 inches to about 0.003 inches.
In a particular example embodiment, the first step surface is
offset from the second step surface about 0.006 inches.
[0007] The invention also encompasses an extractor mountable on a
breech block of a self-loading firearm. In this example embodiment,
the extractor comprises a body attachable to the breech block. The
body has a hook positioned at one end thereof. A pivot pin is
mounted on the body for pivotally attaching the body to the breech
block. A surface is positioned on the body between the pivot pin
and the hook. The surface comprises at least first and second
surface portions, the first surface portion being offset relatively
to the second surface portion. In this example the first surface
portion comprises a plurality of step surfaces including at least a
first step surface, a second step surface, and a third step
surface. The first step surface is offset relatively to the second
step surface. The second step surface is offset relatively to the
third step surface. In an example embodiment, the first step
surface is offset from the second step surface by a first distance,
and the second step surface is offset from the third step surface
by a second distance, the first and second distances being equal to
one another. By way of example, the first and second distances may
range from about 0.009 inches to about 0.003 inches. In a
particular example, the first and second distances are about 0.006
inches. In an example embodiment, the second step surface may be
positioned between the first and the third step surfaces. The first
surface portion may be positioned proximate to the hook, and the
first step surface may also be positioned proximate to the
hook.
[0008] The invention also encompasses an extractor mountable on a
breech block of a self-loading firearm. In an example embodiment,
the extractor comprises a body attachable to the breech block, the
body having a hook positioned at one end thereof. A pivot pin is
mounted on the body for pivotally attaching the body to the breech
block. A surface is positioned on the body between the pivot pin
and the hook. The surface comprises at least first and second
surface portions. The first surface portion is offset relatively to
the second surface portion in this example embodiment. The first
surface portion comprises at least first and second step surfaces.
The first step surface is offset relatively to the second step
surface. In an example embodiment, the first surface portion is
positioned proximate to the hook. The first step surface may also
be positioned proximate to the hook.
[0009] In an example embodiment, the first step surface may be
offset from the second step surface from about 0.009 inches to
about 0.003 inches. In a particular embodiment, the first step
surface is offset from the second step surface about 0.006
inches.
[0010] The invention encompasses another example embodiment of an
extractor mountable on a breech block of a self-loading firearm by
means of a pivot pin. In this example, the extractor comprises a
body attachable to the breech block and having a hook positioned at
one end thereof. An opening is positioned in said body for
receiving the pivot pin. A surface is positioned on the body
between the opening and the hook. The surface comprises at least
first and second surface portions in this example. The first
surface portion is offset relatively to the second surface portion.
The first surface portion comprises a plurality of step surfaces
including at least a first step surface, a second step surface, and
a third step surface. The first step surface is offset relatively
to the second step surface and the second step surface is offset
relatively to the third step surface.
[0011] By way of example, the first step surface may be offset from
the second step surface by a first distance, and the second step
surface may be offset from the third step surface by a second
distance, the first and second distances being equal to one
another. In a further example, the first and second distances may
range from about 0.009 inches to about 0.003 inches. In a
particular example, the first and second distances are about 0.006
inches. The second step surface may be positioned between the first
and the third step surfaces. The first surface portion may be
positioned proximate to the hook, and the first step surface may
also be positioned proximate to the hook in example embodiments of
the invention.
[0012] The invention also encompasses a slide for a self-loading
pistol. In an example embodiment, the slide comprises a breech
block having a breech face. An extractor is mounted on the slide
adjacent to the breech face. The extractor comprises a body having
a longitudinal axis oriented transversely to the breech face. The
body comprises a hook projecting beyond the breech face. A pivot
pin is mounted on the slide. The pivot pin is oriented
perpendicular to the longitudinal axis of the body. The body is
pivotably mounted on the pivot pin. A surface is positioned on the
body between the pivot pin and the hook. The surface comprises at
least first and second surface portions. The first surface portion
is offset toward the breech block relatively to the second surface
portion. The first surface portion comprises at least first and
second step surfaces. The first step surface is offset toward the
breech block relatively to the second step surface. In some example
embodiments, the first surface portion is positioned proximate to
the hook, and the first step surface may also be positioned
proximate to the hook. The first step surface may be offset from
the second step surface from about 0.009 inches to about 0.003
inches. In a particular example embodiment, the first step surface
is offset from the second step surface about 0.006 inches.
[0013] The inventions also encompasses a slide for a self-loading
pistol. In an example embodiment, the slide comprises a breech
block having a breech face. An extractor is mounted on the slide
adjacent to the breech face. The extractor comprises a body having
a longitudinal axis oriented transversely to the breech face. The
body comprises a hook projecting beyond the breech face. A pivot
pin is mounted on the slide. The pivot pin is oriented
perpendicular to the longitudinal axis of the body, the body being
pivotably mounted on the pivot pin. A surface is positioned on the
body between the pivot pin and the hook. The surface comprises at
least first and second surface portions. The first surface portion
comprises a plurality of step surfaces including at least a first
step surface, a second step surface, and a third step surface. The
first step surface is offset toward the breech block relatively to
the second step surface. The second step surface is offset toward
the breech block relatively to the third step surface.
[0014] In an example embodiment, the first step surface is offset
from the second step surface by a first distance, and the second
step surface is offset from the third step surface by a second
distance, the first and second distances being equal to one
another. By way of example, the first and second distances range
from about 0.009 inches to about 0.003 inches. In a particular
embodiment, the first and second distances are about 0.006 inches.
The second step surface may be positioned between the first and the
third step surfaces. In a particular example embodiment, the first
surface portion is positioned proximate to the hook and the first
step surface is also positioned proximate to the hook.
[0015] The invention further comprises a self-loading pistol. In
one example embodiment, the pistol comprises a slide having a
breech block with a breech face. An extractor is mounted on the
slide adjacent to the breech face. The extractor comprises a body
having a longitudinal axis oriented transversely to the breech
face. The body comprises a hook projecting beyond the breech face.
A pivot pin is mounted on the slide. The pivot pin is oriented
perpendicular to the longitudinal axis of the body. The body is
pivotably mounted on the pivot pin. A surface is positioned on the
body between the pivot pin and the hook. The surface comprises at
least first and second surface portions. The first surface portion
is offset toward the breech block relatively to the second surface
portion. The first surface portion comprises at least first and
second step surfaces. The first step surface is offset toward the
breech block relatively to the second step surface.
[0016] The first surface portion may be positioned proximate to the
hook in one example. The first step surface may also be positioned
proximate to the hook. By way of further example, the first step
surface may be offset from the second step surface from about 0.009
inches to about 0.003 inches. In a particular example, the first
step surface is offset from the second step surface about 0.006
inches.
[0017] In another example embodiment, the self-loading pistol
comprises a slide having a breech block with a breech face. An
extractor is mounted on the slide adjacent to the breech face. The
extractor comprises a body having a longitudinal axis oriented
transversely to the breech face. The body comprises a hook
projecting beyond the breech face. A pivot pin is mounted on the
slide. The pivot pin is oriented perpendicular to the longitudinal
axis of the body, the body being pivotably mounted on the pivot
pin. A surface is positioned on the body between the pivot pin and
the hook. The surface comprises at least first and second surface
portions. The first surface portion is offset toward the breech
block relatively to the second surface portion. The first surface
portion comprises a plurality of step surfaces including at least a
first step surface, a second step surface, and a third step
surface. The first step surface is offset toward the breech block
relatively to the second step surface, the second step surface is
offset toward the breech block relatively to the third step
surface.
[0018] By way of example, the first step surface is offset from the
second step surface by a first distance, and the second step
surface is offset from the third step surface by a second distance,
the first and second distances being equal to one another. The
first and second distances may range from about 0.009 inches to
about 0.003 inches. In a particular example, the first and second
distances are about 0.006 inches.
[0019] In an example embodiment, the second step surface is
positioned between the first and the third step surfaces. The first
surface portion may be positioned proximate to the hook, and the
first step surface may also be positioned proximate to the
hook.
[0020] The invention also encompasses a method for fitting an
extractor to a slide of a self-loading pistol. In an example
embodiment, the slide comprises a breech block having a breech
face, and the extractor comprises a body having a longitudinal axis
and a hook. A surface is positioned on the body, the surface
comprising a plurality of step surfaces, each of the step surfaces
being offset relatively to one another in this embodiment. One
example method comprises: [0021] positioning the body on the slide
adjacent to the breech block with the longitudinal axis oriented
transversely to the breech face and the hook extending beyond the
breech face, one of the step surfaces being in contact with the
slide; [0022] measuring a distance between the hook and a point on
the slide proximate to the breech face; [0023] comparing the
distance with a desired distance; [0024] removing the one step
surface in contact with the slide from the body if the distance is
greater than the desired distance; and [0025] repeating the
positioning, measuring, comparing and removing steps until the
distance is less than or equal to the desired distance.
[0026] Removing the step surfaces may be effected by grinding in a
particular example. Other removal methods include sanding, milling
and filing. Further by way of example, removing the one step
surface comprises reducing a thickness of the body by about 0.009
inches to about 0.003 inches. In a particular example, removing the
one step surface comprises reducing a thickness of the body by
about 0.006 inches. An equal thickness of the body may be removed
upon each of the removing steps.
[0027] In another example embodiment of a method for fitting an
extractor to a slide of a self-loading pistol, the slide comprises
a breech block having a breech face and the extractor comprises a
body having a longitudinal axis and a hook. A surface is positioned
on the body, the surface comprising a plurality of step surfaces
including at least a first step surface, a second step surface, and
a third step surface. The first step surface is offset relatively
to the second step surface, the second step surface is offset
relatively to the third step surface. In this example embodiment,
the method comprises: [0028] positioning the body on the slide with
the longitudinal axis oriented transversely to the breech face and
the hook extending beyond the breech face, the first step surface
being in contact with the slide; [0029] measuring a distance
between the hook and a point on the slide proximate to the breech
face; [0030] comparing the distance with a desired distance; [0031]
removing the first step surface from the body if the distance is
greater than the desired distance; [0032] positioning the body on
the breech block with the longitudinal axis oriented transversely
to the breech face and the hook extending beyond the breech face,
the second step surface being in contact with the slide; [0033]
measuring a distance between the hook and a point on the slide
proximate to the breech face; [0034] comparing the distance with a
desired distance; [0035] removing the second step surface from the
extractor if the distance is greater than the desired distance.
[0036] Removing the step surfaces may be effected by grinding by
way of example. Other removal methods include sanding, milling and
filing. Removing the first step surface may comprise, for example,
reducing a thickness of the body by about 0.009 inches to about
0.003 inches. In a particular example, removing the first step
surface comprises reducing a thickness of the body by about 0.006
inches. Removing the second step surface may comprise, for example,
reducing a thickness of the body by about 0.009 inches to about
0.003 inches. In a particular example, removing the second step
surface comprises reducing a thickness of the body by about 0.006
inches. In a further example, an equal thickness of the body is
removed upon removing each of the first and second step
surfaces.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] FIG. 1 is an isometric view of a self-loading firearm;
[0038] FIG. 2 is a partial sectional isometric view of a portion of
the slide and breech block of the firearm shown within the broken
line circle in FIG. 1;
[0039] FIG. 3 is a longitudinal section view of the breech block
and extractor shown in FIGS. 2 and 3; and
[0040] FIG. 4 is an isometric view of an example extractor
according to the invention.
DETAILED DESCRIPTION
[0041] FIG. 1 shows an isometric view of a self-loading firearm 10,
in this example a pistol. Pistol 10 comprises a frame 12 on which
are mounted a barrel 14 and a slide 16. As shown in FIG. 2, slide
16 comprises a breech block 18 having a breech face 20. An
extractor 22 is mounted on the slide 16/breech block 18. Extractor
22 comprises a body 24 having a longitudinal axis 26 oriented
transversely to the breech face 20. A hook 28 is positioned at one
end of the body 24 and projects beyond the breech face 20.
[0042] As shown in FIG. 3, body 24 of extractor 22 is mounted to
the slide 16/breech block 18 via a pivot pin 30. Pivot pin 30 may
be integrally formed with body 24 or it may be a separate component
received within an opening 32 in body 24 (see FIG. 4). Pivot pin 30
is oriented perpendicular to the longitudinal axis 26 of the body
24 to permit pivoting motion of the body relative to the slide
16/breech block 18. A spring element 34 is positioned between the
body 24 and the slide 16/breech block 18 to bias the hook 28 toward
the breech block 18.
[0043] FIG. 4 shows the extractor 22 in detail. Body 24 comprises a
surface 36 positioned between the pivot pin 30 (or opening 32) and
the hook 28. Surface 36 is divided into first and second surface
portions 38 and 40. Surface portion 38, in this example embodiment,
positioned proximate to the hook 28, is offset relatively to the
surface portion 40. Surface portion 38 is further divided into step
surfaces, in this example, first, second and third step surfaces
42, 44 and 46. In the embodiment shown, the first step surface 42
is positioned proximate to the hook 28. The respective offset
distances 48 and 50 between the step surfaces 42 and 44 and 44 and
46 may range from about 0.009 inches to about 0.003 inches. It has
been found advantageous to have the offset distances equal to one
another, at a distance of about 0.006 inches for practical purposes
as explained below.
[0044] As shown in FIG. 3, when the body 24 of the extractor 22 is
mounted on the slide 16/breech block 18, surface 36, and,
consequently, the step surfaces 42, 44 and 46, face the breech
block 18 (these surfaces are not numbered for clarity in FIG. 3).
The spring element 34 biases one of the step surfaces into contact
with the breech block 18. In FIG. 3, step surface 42 is shown in
contact with the breech block. When in the configuration shown in
FIG. 3, with one of the step surfaces in contact with the breech
block 18, it is desirable that the distance 52 between the hook 28
and a point 54 the opposite wall 56 of the breech block 18 (known
as the "bar" dimension) be held within a specified tolerance. The
tolerance will depend on the particular pistol 10. For an .45
caliber pistol such as the Model 1911 for example, the acceptable
tolerance on the bar dimension 52 is +/-0.003 inches. This
tolerance range helps to ensure reliable extraction and feeding of
the ammunition during operation.
[0045] Pistol 10 operates on the locked breech recoil principle,
wherein recoil energy from the discharging round is harnessed to
extract and eject the spent casing from the barrel chamber, cock
the hammer, and strip a round from the magazine and chamber it in
the barrel. Immediately upon discharge of a round, the breech block
and barrel, being initially locked together, recoil together
relatively to the frame over a short distance in a direction
opposite to the direction of discharge. Motion of the barrel is
then hafted, and the breech block separates from the barrel. The
hook of the extractor is engaged with a groove in the base of the
casing, and as the breech block separates from the barrel the hook
extracts the spent casing from the chamber. The casing is ejected
to one side by the asymmetrical pull of the extractor. The breech
block continues its motion away from the barrel, cocking the
hammer. The kinetic energy of the breech block is captured by a
recoil spring, which then moves the breech block in the opposite
direction toward the barrel. During this motion the breech block
passes over the magazine, from which it strips the next round to be
chambered. As the breech block moves toward the barrel it forces
the next round into the chamber of the barrel. The breech block and
barrel lock together and move together over a short distance into
the "battery" position from which the pistol was initially
discharged. As the round is chambered the hook of the extractor
engages the groove in the casing, pivoting as required to ensure
proper engagement.
[0046] With reference again to FIG. 3, if the bar dimension 52 is
smaller than the allowable tolerance, then stripping and chambering
of the next round is inhibited. If the bar dimension 52 is larger
than the allowable tolerance, then extraction of the spent casing
is erratic. For pistols wherein the bar dimension tolerance is
small, such as the Model 1911, the extractor 22 as manufactured is
not an interchangeable part, but must be fit to each pistol to
ensure that the bar dimension tolerance is met. Fitting the
extractor requires that an extractor be mounted on the slide
16/breech block 18, the bar distance measured, and then, if the bar
dimension is too large, the extractor must be removed and material
must be removed from the surface portion 38 which contacts the
breech block 18. This procedure is repeated until either the bar
dimension is within the tolerance or the bar dimension is too small
(because too much material was removed), in which case the
extractor is discarded and the process is repeated with a new
extractor.
[0047] The process of fitting and extractor to a slide 16/breech
block 18 is improved through the use of the extractor 22 according
to the invention. By using a plurality of step surfaces 42, 44, 46
on the surface portion 38 as shown in FIG. 4, an armorer can
readily remove a known amount of material from the surface portion
38 without the need for measuring the thickness of the extractor
22. When each step surface has a known offset dimension, the
armorer can visually determine how much material has been removed,
or is available for removal. Elimination of the measuring step
greatly simplifies the extractor fitting process and allows fitting
of the extractor in the field, using a go-no go gauge rather than a
micrometer or calipers to measure the bar dimension 52.
[0048] The invention also encompasses a method for fitting an
extractor as described above to a slide/breech block of a
self-loading pistol. In one example embodiment, the method
comprises: [0049] positioning the extractor body 24 on the slide 16
adjacent to the breech block 18 with its longitudinal axis 16
oriented transversely to the breech 20 and the hook extending
beyond the breech face, one of the step surfaces 42 being in
contact with the slide; [0050] measuring the bar dimension
(distance 52) between the hook and a point on the slide proximate
to the breech face (i.e., the opposite wall 54 of the breech block
18); [0051] comparing the bar dimension (distance 54) with a
desired distance; [0052] removing one step surface (42) in contact
with the slide 16 from the body 24 if the bar dimension (distance
52) is greater than the desired distance; and [0053] repeating the
positioning, measuring, comparing and removing steps until the bar
dimension (distance 52) is less than or equal to the desired
distance.
[0054] In a practical example, the extractor 22 may have three step
surfaces 42, 44 and 46 as shown in FIG. 3. An example method used
with this extractor comprises the following steps: [0055]
positioning the body 24 of the extractor 22 on the slide 16 with
the longitudinal axis 26 oriented transversely to the breech face
20 with the hook 28 extending beyond the breech face, the first
step surface 42 being in contact with the slide; [0056] measuring
the bar distance 52 between the hook 28 and a point 54 on the slide
proximate to the breech face; [0057] comparing the distance with a
desired distance; [0058] removing the first step surface 42 from
the body if the distance is greater than the desired distance;
[0059] positioning the body 24 on the slide 16 with the
longitudinal axis 26 oriented transversely to the breech face 20
with the hook extending beyond the breech face, the second step
surface 44 being in contact with the slide; [0060] measuring a
distance between the hook 28 and the point 54 on the slide 16
proximate to the breech face 20; [0061] comparing the distance with
the desired distance; [0062] removing the second step surface 44
from the extractor 22 if the distance is greater than the desired
distance.
[0063] Removal of the step surfaces is effectively accomplished by
grinding. Sanding, milling and filing may also be used to remove
the step surface. For practical extractors, the offset 48, 50 of
the step surfaces may range between about 0.009 inches to about
0.003 inches. Thus, as each step surface is removed, the body 24 is
reduced in thickness by about 0.009 inches to about 0.003 inches
depending on the size of the offset. For a Model 1911 pistol having
a bar distance tolerance of about +/-0.003 inches, a step surface
offset of about 0.006 inches is advantageous. While the offset
distances are all equal to one another in this example, they could
also have different values.
* * * * *